So you want to put heat on a DA, let's look at his weaknesses and what he's done well.
Weakness:
Drafting
Positives:
Wins: 25 year 1, 40 years 2, on pace for 50 year 3
Flexibility: Numerous assets, Important draft picks, Cap flexibility
Roster: A roster that is serviceable, putting together an exciting brand of basketball, and plays together.
Playoffs: year 2 of the rebuild made the playoffs, and year 3 sits at the 3rd seed currently.
I see more positives than negatives. There's no one I'd rather have steering the ship than DA.
One last point: There was no one available this deadline other than Howard and Horford. Overpaying on rentals could potentially set the rebuild back. Look at the numerous articles about it.